Rule 5 pick Josh Fields made the club, as did relievers Rhiner Cruz and Hector Ambriz.

RHP Edgar Gonzalez was optioned to Class AAA Oklahoma City.

White, 24, was an early favorite to make the Astros’ rotation and caught first-year manager Bo Porter’s eye during the start of spring training. But White’s exhibition numbers (1-1, 6.86 ERA, 2.03 WHIP) paled compared to Peacock’s.

The 25-year-old who struggled in Class AAA with Oakland last season became one of the Astros’ top spring starters. Peacock holds an 0-1 record with a 3.20 ERA, striking out 15 in 19.2 innings and walking only six. His 1.11 WHIP, impressive command and increasing confidence pushed him into the Astros’ first five. Peacock’s only allowed two earned runs in his last 16 innings and becomes the youngest starter in the Astros’ rotation.

“He really just looked like he got stronger in each and every outing,” said Porter, who previously worked with Peacock with the Washington Nationals.

Porter added: “The (pitches) got more crisp. You started looking at the breaking ball really starting to get late depth.”

Peacock was acquired by the Astros in the February Jed Lowrie trade with Oakland. With Chris Carter expected to start in left field, the Astros could have two regular 2013 players via the Lowrie deal.

“I saw (Peacock) really, really good in (2011),” Porter said. “Like I told him, he looks like the guy I saw (then).”

Peacock was a combined 15-3 with a 2.39 ERA and 177 strikeouts in 146.2 innings in Class AAA and AA with the Nationals in 2011. He went 12-9 with Oakland’s AAA team last season, but posted a 6.01 ERA and has acknowledged having a poor year.